1. Field of the Invention
The present invention relates generally to electronic musical instruments and in particular, to new and improved polyphonic digital musical instrument variations that receive articulated input via an improved Surface Impression Transducer for processing via an Articulation Recognition Processor for ultimate modulation of various electronic musical synthesizers and digital recording samplers, preferably implementing the Articulation Sampling Method.
2. Description of the Related Art
Articulation of acoustic instruments, or how you play them, is what gives the acoustic instrument its depth of sound, sonic coloring and inherent aural uniqueness. This is not always the case with electronic instruments. Successful musical articulation of musical analog/digital synthesizers and digital recording samplers requires full modulation contouring capabilities from the human interface controller, or the sound may be perceived as dry, repetitive and dull.
Electronic keyboards and drum pad controllers constitute the majority of marketable electronic instrument controllers. Electronic keyboards, drum pads and a few specialty controllers offer a generally fixed articulation realm to the musician.
Original monophonic note-on only electronic synthesizer keyboards had limited articulation capability. This was eventually improved with the invention of polyphonic capability allowing one to press multiple keys at a time, for a chord for instance, or individual keys or a range of keys, to generate unique synthesizer sounds or voicings. Keyboard articulation was further enhanced with additional user modulation capability via pitch and modulation wheels, ribbon controllers, key attack and release velocity, key pressure or after-touch circuits and weighted keys for a traditional or familiar action.
Current electronic drum pad controllers are monophonic in operation and sonically one-dimensional, meaning they process a single impact at a time with force typically being the only processable variable utilized to trigger a sound modulated to a volume level proportional to some arbitrary point along an impact event curve. Most designs are based on piezoelectric transducer technology that generates a voltage proportional to an arbitrary point along the impact event curve. An image of a piezoelectric transducer 202 is shown in FIG. 2. An image of a commercial “piezo” drum pad 204 is also shown. Piezoelectric transducers suffer from being inherently susceptible to external vibrations, which can cause false triggering. For example, direct mechanical or induced vibration from high power sound reinforcement systems or cross triggering from a strike on one of two adjacent pads literally triggers both. An adjustable voltage limiting circuit could be used to overcome this issue at a cost of reduced sensitivity, further limiting articulation. Piezoelectric designs may also suffer from electro-mechanical response latency causing a discernible delay between the impact event and eventual sound generation, becoming increasingly noticeable during well-articulated or allegro (fast) playing.
Electronic drum pad designs utilizing alternate sensor technologies have been attempted to overcome the limitations of piezoelectric designs through various configurations of piezoelectric transducers, force sensing resistor (FSR) and digital signal processing (DSP) circuits. Some designs incorporate a single action full perimeter rim sensor typically used to trigger snare ‘rim-shot’ sounds. Even with the microsecond response of the FSR sensor, some designs still experience impact-to-sound latency through incorrect software or hardware implementation.
Key features of the FSR over the piezoelectric transducer include improved latency and reduced susceptibility to false triggering. Some interesting FSR based designs incorporate 2 or 3 separate FSRs, typically arranged in fractional pie form factor utilized to trigger discrete synthesizer voicings but individually include no additional modulation or articulation capabilities.
One interesting design available on the market (U.S. Pat. No. 6,815,602) has its FSR mating circuit arranged in a spiral format to resistively measure impact location in the single center-to-edge vector only along each step of the 127 concentric ring spiral in 11″ circular form factor for an approximate fixed 0.087″ physical resolution. That design provides a single monophonic center-to-edge vector modulation variable in addition to impact force via piezoelectric transducer. To note, the addition of that single extra modulator allows the musician to create comparatively impressive dynamic sound.
Another FSR based design (U.S. Patent Publication No. 2011/0167992) claims to detect multiple touches. It is described as a multilayer FSR approach; one in spiral format and a second FSR layer in a complex segmented trace configuration format where each segment provides a specific, identifying resistance. The first FSR layer circuitry schematic and layout detail are shown with alternating segments bussed together, the first to provide a singular surface force measurement. The second FSR layer circuitry is shown in a switched multi-tap variable serial/parallel resistor voltage divider network with a multitude of applied resistance shunting and undisclosed ‘complex mathematical functions’ used to determine touch position. The schematic detail shows electrical configurations for single and dual instances, but configuration of any key detailed circuitry are also not disclosed. The circuitry as shown suggests if more than one actuation were to occur simultaneously along the same network, linear actuation would likely inject an indeterminate resistance into the tapped segment resistance sum, so the expected positional information results would be skewed or indeterminate.
DSP based drum pad sensors perform signal analysis of a transducer's output and have algorithms programmed to attempt to mask or minimize the limitations inherent in component selection or implementation. Sometimes a bit of tom-foolery is incorporated within the microprocessor or DSP algorithm to simulate articulation by applying arbitrary random or pre-determined fixed modulation values. By design, these systems play themselves rather than allow the accomplished musician to actually perform their intent on the instrument.
Another example of a very playable Musical instrument digital interface (MIDI) trigger currently is described in U.S. Pat. No. 5,434,350. An ergonomic array of strategically placed switch activated pressure transducers are mounted in a fine wood finished enclosure. This design presents a multitude of sounds and modulations available at the musician's fingertips. Similar in operation to the accordion, velocity (force) sensitive switches trigger and modulate various notes or sounds and additional switches assignable to modify those sounds similar to the registers of an accordion.
Within 10 years, electronic keyboard modulation capability vastly improved as did customer satisfaction as well as the resulting increase in sales. However, in the case of electronic drum pads, few articulation improvements have been made at all. The electronic drum pad has been around for 30+ years with virtually no change in modulation capability. Major product enhancements have only been shell cosmetic and surface configuration to mimic acoustic drum look and feel. FIG. 1 shows an adjustable head tension mechanism 102 and a physical aesthetic emulation of acoustic drums 104.
Thus, there is a need for new and improved digital musical instruments that advances over the state of the art. While a variety of MIDI controller designs exist, there is a need for fresh approach to improved polyphonic digital music instruments architecture and methods with making the same.
The present invention addresses this and the objectives by providing new and improved polyphonic digital musical instrument that receives input via an improved Surface Impression Transducer and Articulation Recognition Processor, preferably used in conjunction with the Articulation Sampling Method, to address the limitations of and to advance the stat of the art.